The national crisis, within the UK, is the problem of whether the second syllable is pronounced 'ree' or 'ray' ('ree' it turns out, for this particular Theresa) and whether the first syllable is truncated (no), as this passage from a Buzzfeed article (helpfully jpegged by author @jamesrbuk) explains:
Language Log looked at that vowel yesterday.
The international crisis is: what's going on with that 's'? In American English, the 's' means /s/, but note that the Buzzfeed article didn't even mention the possibility of (mis)pronouncing it with an /s/. In British English, it's a /z/.
Theresa is not alone. There are other s-ful names that British English routinely pronounces with /z/, and American English usually pronounces with /s/. These include:
- Leslie / Lesley (which British folk will tell you is the feminine spelling--Americans don't follow that distinction) and the truncated form Les
- Lisa sometimes (hear here - this is the only UK voice I've found on name-pronouncing sites)
- Joseph sometimes (compare here)
- Louisa? (I only recently learned that other people say LouWEEza, whereas I always said lewISSa. Maybe I'm just a weirdo, but I'm an American weirdo. Here's some discussion. About Louisa, not about whether I'm a weirdo. That matter has been settled. Louise has a /z/ in both countries.)
But--and this is a big BUT--these are names, so anything can happen. Names are subject to fashions and to individual whimsy. In particular, I suspect that the /s/ in the 'sl' names varies in America. In fact, I know it does in Wesley. The name (for the same character) is pronounced on Big Bang Theory with a definite /z/. Since the /s/ pronunciation is used by the character's own mother, this just seems disrespectful. ;)
In on-line conversations, I've seen Americans calling the /z/ version of 'Theresa' "posh". (They were American, so maybe posh isn't the word they used, but it was the meaning.) That may be because of the association with British accents or the Frenchness of the /z/ (as in Thérèse).
I can't say that I ever noticed any /z/ pronunciations of Theresa while growing up in America. Mother Theresa had an /s/ and so did the Theresa I went to school with. She used to ask if she could carry my lunch box for me to show that we were friends. When we'd get to the corner where we should part ways, I'd ask for my lunchbox back and she would laugh and cross the street that I wasn't allowed to cross and run away with my lunchbox. Yes, the use of habitual verb forms there indicates that it happened more than once. She always promised that it wouldn't happen again if I just trusted her...
Alicia and Marcia are another couple of names that often throw me when I hear them in the UK. Whereas the Alicia I grew up with was "aLEEsha", in the UK it's "aLISSeeya". There is bound to be variation in the US on these, especially since in Spanish Marcia would have a "seeya" pronunciation.
There are, of course, many other names that are pronounced differently in the two countries. On the theme of national leaders' names, I have another post on Barack Obama. You might find discussion of some of the others by clicking on the names tag. Important to note here that the /z/ in these names is not particularly related to the /z/ that's used in a lot of British nicknames. While Theresa may become Tezza, the z in that case is coming (believe it or not) from the /r/, just as it does for Jeremy --> Jezza. I've another post on that phenomenon.